If a customer waits for your homepage photo, changing its format might help. It won’t fix a photo that’s three times larger than the space it fills. For most small business sites, we recommend WebP as the easy starting point. AVIF is worth testing on large photos when the smaller file improves loading without adding delivery problems.
So, how do you choose without turning every image upload into a technical project? Start with the job each image needs to do.
Key Takeaways
- WebP is a reliable default when you want smaller images with broad browser and CMS support.
- AVIF can make detailed photos smaller, but the result depends on the image and how it’s encoded.
- A fallback lets you offer AVIF without leaving visitors on older browsers with a blank space.
- Neither format improves rankings on its own. Measure page speed and keep the image clear enough to help visitors decide what to do next.
WebP vs AVIF: File Size, Quality, and Processing
Both next-generation image formats can reduce image weight compared with legacy formats. But a smaller file size isn’t automatically better if the image quality suffers and customers lose details they need to see.
Compression and visual quality
The WebP image format offers lossy compression, which removes some image data to create smaller files, and lossless compression, which preserves image data but may produce a larger file. Its transparency support also makes it useful for some graphics and logos.
The AVIF image format often has an advantage with detailed photographic images, especially when files look equally good. A shop’s full-width interior photo or gallery of finished projects may be worth testing in AVIF. Chrome’s guidance on modern image formats explains why both formats belong in a performance review.
Compression efficiency varies by image. Detailed photographic images, flat illustrations, and graphics with text can produce different results. We compare the finished files side by side, then check their sizes.
Encoding and decoding cost
The AVIF image format is based on the AV1 video codec and was developed by the Alliance for Open Media. It supports a wider color depth and HDR workflows. Most small business sites won’t need HDR to show a team photo, menu item, or service vehicle well.
The tradeoff is processing. AVIF can take more work to create and decode than WebP. That doesn’t mean every AVIF image will load slowly. It means the smallest file on your computer isn’t automatically the fastest image on a visitor’s phone.
Match the Format to the Image’s Job
A site doesn’t need one format for everything. We get better results when we consider where an image appears and what a visitor needs to learn from it.
Use AVIF where photos carry the page
Consider AVIF for large, detailed photographic images, such as a hero photo, property gallery, or portfolio page with many images. Keep it when the difference is visible in the file size, not in unwanted blur or color changes. If a smaller AVIF still looks right, visitors may have less data to download.
Look closely at faces, product edges, small print on packaging, and gradual color changes in photographic images. Those details matter more than a compression setting. Keep the original image so you can make a new version later.
Keep graphics and small assets simple
WebP is often the practical choice for raster illustrations, thumbnails, and transparent graphics. A tiny icon may offer little room for savings, so adding another format may create work without improving the page.
For a simple logo or icon, consider SVG if your website supports it and the artwork is suitable. It’s a vector format that stays sharp at different sizes. Keep PNG when you need a dependable raster fallback, particularly for a transparent asset. The goal isn’t to convert every file. It’s to make the images people notice load efficiently.
Check Browser and CMS Support Before Switching
Your preferred format must work across the browsers your customers use and the tools your team uses to publish. A file that uploads successfully isn’t always one your website can resize or serve correctly.
Browser support favors a fallback
Current versions of Chrome, Firefox, Edge, and Safari support WebP and AVIF. WebP has the longer history of support, so it’s generally the simpler choice when you want one modern format. Older browser versions are why it’s worth checking browser support on your customers’ devices before relying on AVIF.
MDN’s image format guide is a useful reference when you’re checking compatibility. For a local business, test on actual devices too: open your homepage and booking page on your team’s phones, and check how photographic images appear.
CMS support includes the whole upload process
WordPress added WebP support in version 5.8 and AVIF support in version 6.5, but AVIF handling can still depend on your hosting environment. Check whether your site creates the smaller image sizes it needs after upload. Then confirm those sizes appear on the live page.
Some image services and CDNs generate modern formats automatically. Before adding a plugin, check your setup’s conversion efficiency: can it generate and serve needed variants without extra maintenance? We prefer a workflow someone can maintain next month, not a collection of overlapping converters. For WordPress, our guide to compressing images for faster loading covers the upload habits that matter alongside format choice.
Serve AVIF With a Dependable Fallback
Want to try AVIF without betting the page on browser support? Keep another version of the same image ready. Visitors should see the intended photo even if their browser can’t use your first choice.
Use the picture element for important images
The HTML picture element lets a browser choose among versions of one image. For important photographic images, set an AVIF source first, a WebP source next, and a JPEG or PNG file in the img element. This fallback strategy lets the browser use the first format it supports. MDN’s picture element reference shows how the sources and fallback fit together.
Keep meaningful alt text on the img element and provide width and height so space is reserved while the image loads. If your CMS or image service builds this markup for you, inspect the published page. Don’t assume the editor preview shows every version visitors receive.
Keep automated delivery predictable
A CDN may choose an image based on the browser’s Accept request header instead of using picture. That can work, but caching needs care. If the CDN gives every visitor the same cached response regardless of format support, some may receive an image their browser can’t display.
Ask your provider how its cache separates formats, whether it sends the correct image MIME type, and what happens when AVIF isn’t supported. Keep the original or a conventional fallback available. Then test the live page, not only the file saved in your media library.
Image Format Helps SEO Through Page Experience
Google doesn’t give a page a ranking bonus for an .avif or .webp extension. The potential benefit is indirect: optimized images can improve page loading speed, helping visitors see your offer and reach a call, booking, or quote button.
Watch the image that affects LCP
Largest Contentful Paint (LCP) measures when the main visible content appears. A large homepage image can be that element. Reducing its transfer size may help, but a slow server, late image discovery, or heavy scripts can still delay it.
We aim for LCP under 2.5 seconds, Interaction to Next Paint (INP) under 200 milliseconds, and Cumulative Layout Shift (CLS) under 0.1. These Core Web Vitals thresholds reflect a good experience across real visits. Image compression can help LCP, but it won’t fix buttons delayed by JavaScript. Setting image dimensions can help prevent shifts. Our technical SEO checklist for small businesses puts these checks in context, including how images fit into broader site performance.
Keep images useful and discoverable
Format is only one part of image SEO. Google also recommends descriptive page context and useful image information in its image SEO best practices. For photographic images, write alt text that describes the image when it adds meaning. A photo of a completed kitchen should help a visitor understand the work, not carry a stack of keywords.
Load the main image promptly. Lazy loading is better suited to images farther down the page, where it can save bandwidth without delaying that first impression. If you’re adjusting those settings, review how to use lazy loading without harming SEO.
Test the Change on Real Pages
We wouldn’t convert an entire photo library based on one compression result. Start with a high-traffic page that has a large image, then compare it before and after the change.
Compare the same image fairly
Resize each version to the dimensions the page needs. Compare WebP and AVIF at settings that preserve acceptable visual quality, and inspect both on a phone. Record the displayed dimensions and transferred file size. A 3,000-pixel source used in a small card needs resizing before the comparison tells you much.
Test the homepage hero, a service-page photo, and a thumbnail separately. These photographic images may perform differently in each format. If AVIF saves little on one asset, WebP may be the easier choice there. If it saves substantially on a large photo without harming quality, keep it in the delivery mix.
Measure what visitors experience
Run the page through PageSpeed Insights and review its mobile results. Use Search Console’s Core Web Vitals report to see patterns across pages. Field data, when available, reflects real visitors; a single lab test is useful for diagnosis, not proof of lasting improvement.
Check that images display in your target browsers, the fallback works, and calls to action remain easy to reach. If images no longer cause the main delay, review site performance beyond format changes. Check hosting, scripts, caching, and plugins.
Frequently Asked Questions
Is AVIF always smaller than WebP?
No. AVIF often compresses detailed photos well, but results vary with the source image and settings. Compare files at similar visual quality. If you can’t see a useful size reduction, there’s no need to add AVIF for that image.
Should every small business convert its images to AVIF?
No. WebP is a sound starting point, especially when your CMS already handles it. Add AVIF where testing shows a clear benefit and your site can provide a reliable fallback. Resize and compress oversized uploads first.
Can changing to WebP or AVIF improve rankings?
Neither format guarantees better rankings. Smaller, well-delivered images can improve page loading speed and user experience, which support SEO. Helpful content, relevant service pages, and a clear path to contact your business still matter.
Make the Format Work for the Page
When a homepage photo loads late, check its dimensions and delivery to improve page loading speed. We usually choose WebP as the default, then test AVIF on large photographic images that may benefit from smaller files.
Keep a fallback, check the live page on mobile, and measure site performance. The useful image is the one that loads promptly, looks clear, and helps your customer take the next step.
